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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1962

Tables of Interference Factors for Use in Wind-tunnel and Ground-effect Calculations for VTOL-STOL Aircraft. Part I - Wind Tunnels Having Width-height Ratio of 2.0

Tables of interference factors for use in wind-tunnel and ground-effect calculations for VTOL-STOL aircraft are presented for wind tunnels having a width-height ratio of 2.0. These tables were machine-calculated and are intended for use with the procedures of NASA Technical Report R-124. These tables are presented without comment.

Interference factor table↗
NASA NTRS1976

Simulation of an automatically-controlled STOL aircraft in a microwave landing system multipath environment

The simulated response is described of a STOL aircraft to Microwave Landing System (MLS) multipath errors during final approach and touchdown. The MLS azimuth, elevation, and DME multipath errors were computed for a relatively severe multipath environment at Crissy Field California, utilizing an MLS multipath simulation at MIT Lincoln Laboratory. A NASA/Ames six-degree-of-freedom simulation of an automatically-controlled deHavilland C-8A STOL aircraft was used to determine the response to these errors. The results show that the aircraft response to all of the Crissy Field MLS multipath errors was small. The small MLS azimuth and elevation multipath errors did not result in any discernible aircraft motion, and the aircraft response to the relatively large (200-ft (61-m) peak) DME multipath was noticeable but small.

Toda, M.↗
NASA NTRS1986

Flight evaluation of a precision landing task for a powered-lift STOL aircraft

A flight research experiment was conducted with the NASA-Ames Research Center's Quiet Short-Haul Research Aircraft to determine the factors which influence the touchdown distribution for a powered-lift STOL aircraft. The pilots were given two tasks for each of a series of precision approaches flown using a microwave landing system (MLS) in simulated instrument meteorological conditions. They flew the aircraft, with forward vision obscured by a screen, to a 100-ft decision height using a flightpath-oriented, color electronic display and one of four levels of control augmentation. Approaches were flown along a nominal 6 deg glidepath, as well as to calibrated offsets at the decision height to establish a variety of initial conditions for the landing task. The screen was removed at the decision height and the pilot was briefed to land in a 200 foot touchdown zone of the STOLport with a sink rate less than 5 ft/sec. Statistical performance envelopes and pilot ratings are used to describe the results of this experiment. The data generated are expected to be useful for establishing STOL aircraft operating requirements and STOL MLS approach criteria.

Watson, D. M.↗
NASA NTRS1973

Study of quiet turbofan STOL aircraft for short-haul transportation. Volume 4: Markets

A marketing study to determine the acceptance and utilization of a STOL aircraft short-haul air transportation system was conducted. The relationship between STOL characteristics and the economic and social viability of STOL as a short-haul reliever system was examined. A study flow chart was prepared to show the city pair and traffic split analysis. The national demand for STOL aircraft, as well as the foreign and military markets, were analyzed.

Source record↗
NASA NTRS1975

STOL aircraft transient ground effects. Part 2: Experimental techniques feasibility study

Procedures for simulating transient effects associated with STOL aircraft landings and takeoffs were examined and a basis was developed for selection of an experimental approach based on consideration of simulation requirements, experimental techniques, facilities, and costs. The results are generally applicable to STOL aircraft employing any of the following powered lift systems: externally blown flap, upper surface blown flap, augmentor wing, or internally ducted jet flap. Scaling relationships were developed to apply the simulation requirements to model test situations. Procedures for the derivation of aerodynamic forces from the measured data were discussed. Various means of expressing the aerodynamic data in forms convenient for use in performance or stability and control applications were described. Five different experimental techniques were presented that depend on two different types of experimental facilities, wind tunnels and test tracks, and involving different types of model motion, and factors pertinent to selection were summarized.

Crowder, J. P.↗
NASA NTRS1980

Flight evaluation of configuration management system concepts during transition to the landing approach for a powered-lift STOL aircraft

Flight experiments were conducted to evaluate two control concepts for configuration management during the transition to landing approach for a powered-lift STOL aircraft. NASA Ames' augmentor wing research aircraft was used in the program. Transitions from nominal level-flight configurations at terminal area pattern speeds were conducted along straight and curved descending flightpaths. Stabilization and command augmentation for attitude and airspeed control were used in conjunction with a three-cue flight director that presented commands for pitch, roll, and throttle controls. A prototype microwave system provided landing guidance. Results of these flight experiments indicate that these configuration management concepts permit the successful performance of transitions and approaches along curved paths by powered-lift STOL aircraft. Flight director guidance was essential to accomplish the task.

Franklin, J. A.↗
NASA NTRS1974

Analytical design and simulation evaluation of an approach flight director system for a jet STOL aircraft

A program was undertaken to develop design criteria and operational procedures for STOL transport aircraft. As part of that program, a series of flight tests shall be performed in an Augmentor Wing Jet STOL Aircraft. In preparation for the flight test programs, an analytical study was conducted to gain an understanding of the characteristics of the vehicle for manual control, to assess the relative merits of the variety of manual control techniques available with attitude and thrust vector controllers, and to determine what improvements can be made over manual control of the bare airframe by providing the pilot with suitable command guidance information and by augmentation of the bare airframe dynamics. The objective of the study is to apply closed-loop pilot/vehicle analysis techniques to the analysis of manual flight control of powered-lift STOL aircraft in the landing approach and to the design and experimental verification of an advanced flight director display.

Klein, R. H.↗
NASA NTRS1973

A manual control theory analysis of vertical situation displays for STOL aircraft

Pilot-vehicle-display systems theory is applied to the analysis of proposed vertical situation displays for manual control in approach-to-landing of a STOL aircraft. The effects of display variables on pilot workload and on total closed-loop system performance was calculated using an optimal-control model for the human operator. The steep approach of an augmentor wing jet STOL aircraft was analyzed. Both random turbulence and mean-wind shears were considered. Linearized perturbation equations were used to describe longitudinal and lateral dynamics of the aircraft. The basic display configuration was one that abstracted the essential status information (including glide-slope and localizer errors) of an EADI display. Proposed flight director displays for both longitudinal and lateral control were also investigated.

Baron, S.↗
NASA NTRS1974

Calculation of aerodynamic characteristics of STOL aircraft

Method predicts lift and pitching moment characteristics of STOL aircraft with externally-blown, jet-augmented wing-flap combinations using potential-flow approach which involves combination of two flow models. Method can accommodate multiple engines per wing panel and part-span flaps.

Dillenius, M. F. E.↗
NASA NTRS1979

Flight experience with advanced controls and displays during piloted curved decelerating approaches in a powered-lift STOL aircraft

A program to assess the feasibility of piloted STOL approaches along predefined, steep, curved, and decelerating approach profiles was carried out with a powered-lift STOL aircraft. To reduce the pilot workload associated with the basic control requirements of a powered-lift aircraft equipped with redundant controls and operating on the backside of the power curve, separate stability augmentation systems for attitude and speed were provided, as well as a supporting flight director and special electronic cockpit displays. The control, display, and procedural features are described for the flight experiment that led to the conclusion that, given an adequate navigation environment, such constrained approaches may be feasible from a pilot acceptance point of view.

Hindson, W. S.↗
NASA NTRS1978

Study to determine operational and performance criteria for STOL aircraft operating in low visibility conditions

The operational and performance criteria for civil CTOL passenger-carrying airplanes landing in low visibilities depend upon the characteristics of the airplane, the nature and use of the ground and airborne guidance and control systems, and the geometry and lighting of the landing field. Based upon these criteria, FAA advisory circulars, airplane and equipment design characteristics, and airline operational and maintenance procedures were formulated. The documents are selected, described, and discussed in relationship to the potential low weather minima operation of STOL aircraft. An attempt is made to identify fundamental differences between CTOL and STOL aircraft characteristics which could impact upon existing CTOL documentation. Further study and/or flight experiments are recommended.

Gorham, J. A.↗
NASA NTRS1972

Four-D guidance of STOL aircraft in the terminal area

The primary objective of advanced STOL aircraft is the improvement of the nation's air transportation system by the elimination of delays and congestions associated with today's air travel. A new guidance technique, referred to as 4-D guidance, is being developed to achieve this objective. The 4-D guidance technique synthesizes complex three-dimensional flight paths from a minimum set of input data and flies the aircraft along the paths according to a prespecified time schedule. The two major elements of a 4-D guidance system are the trajectory synthesizer and the control law. Inputs to the trajectory synthesizer are the three-dimensional coordinates of way points, the turning radii, the speed ranges, the acceleration limits, and the arrival times at time control way points. First, the three-dimensional trajectory is computed by using circular arcs and straight lines. Then the airspeed profile, compensated for wind, is calculated to achieve the desired arrival times. The synthesized trajectory is stored as a time sequence of reference states which the aircraft is forced to track by using a linear feedback law.

Pecsvaradi, T.↗
NASA NTRS1990

Civil Applications For New V/STOL and STOL Aircraft

New designs offer benefits in congested urban areas and remote regions. Report explores potential uses in civil aviation of advanced rotorcraft, vertical/short-takeoff-and-landing (V/STOL) aircraft, and short-takeoff-and-landing (STOL) aircraft. Future opportunities overcome formidable geographic barriers and lack of major airport facilities, bringing fast, flexible transportation to remote areas. Aircraft relieves congestion at airports in densely populated areas by utilizing pads and short runways without interfering with large-air-carrier traffic.

Albers, James A.↗
NASA NTRS1974

An economic assessment of STOL aircraft potential including terminal area environmental considerations, volume 1

The results of an economic and environmental study of short haul airline systems using short takeoff and landing (STOL) aircraft are presented. The STOL system characteristics were optimized for maximum patronage at a specified return on investment, while maintaining noise impact compatibility with the terminal area. Supporting studies of aircraft air pollution and hub airport congestion relief were also performed. The STOL concept specified for this study was an Augmentor Wing turbofan aircraft having a field length capability of 2,000 ft. and an effective perceived noise level of 95 EPNdB at 500 ft. sideline distance. An economic and environmental assessment of the defined STOL system and a summary of the methodology, STOL system characteristics and arena characteristics are provided.

Solomon, H. L.↗